ZHAO Wenjie1,2 , HUANG Deming1,2, WANG Liping1, XUE Qunji1
(1. State Key Laboratory of Solid Lubrication, Lanzhou Institute of Chemical Physics, Chinese Academy of Sciences, Lanzhou 730000, China 2. Graduate School of Chinese Academy of Sciences, Beijing 100049, China)
Abstract: Ultra-thin RTILs films with different chain lengths were successfully prepared on silicon substrates by a dip-coating method. The influence of different chain length on micro/nano-tribological properties of the as-prepared RTILs films was systematically investigated. Thermal stability of the RTILs was evaluated using a Mettler thermal gravity analysis in a nitrogen atmosphere. Chemical compositions of the films were characterized with a multi-functional X-ray Photoelectron Spectrometer. Wetting/dewetting properties were determined by a contact angle measure instrument. The morphologies, nano-friction and nano-adhesion behaviors of RTILs films with different chain lengths were experimentally investigated at the nanoscale using AFM/FFM. Microfriction properties were evaluated by a microtribometers. The investigation revealed that the chain length of the RTILs films significantly affected their nano-friction and adhesion properties, but had little influences their microfriction performance. With the increasing chain length, adhesive force and nanofriction force reduced significantly. The corresponding friction-reduction and anti-wear mechanisms of the tested ultra-thin RTILs films under tested condition were analyzed based on the experimental observation.
Key words: ionic liquid, ultra-thin film, chain length, micro/nano-friction, adhesion ,AFM
E-mail: lpwang@licp.cas.cn
Tribology, Vol. 30, Issue 6, 2010, 614~619
